Mark sampler metadata clean when it is updated This was accidentally left out of the patch: "Pass texture base level to shaders on D3D11" TEST=angle_end2end_tests angle_perftests on d3d11 BUG=587846 Change-Id: I5d801288303cf0e0a3d52c1314aca95c47f02e25 Reviewed-on: https://chromium-review.googlesource.com/328960 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>